Nuclear Spin Relaxation and Electric Quadrupole Frequency Shift of 129 Xe- 131 Xe in Cubic Stemless MEMS Atomic Vapor Cells.

Research on the electric quadrupole frequency shift mechanism and nuclear spin relaxation of 129Xe-131Xe in alkali metal atomic vapor cells fabricated using microelectromechanical systems (MEMS) technology remains in its early stages. Therefore, an in-depth investigation in this field is crucial for enhancing the performance of miniaturized atomic gyroscopes and other quantum devices. This study provides a comprehensive analysis of the electric quadrupole frequency shift and relaxation of 129Xe-131Xe nuclear spins in a stemless cubic MEMS vapor cell. To elucidate the microscopic characteristics of wall interactions, nuclear spin quadrupole interactions with mixed silicon and glass surfaces in MEMS vapor cells were examined. The influence of the angle between the vapor cell's geometric axis and the applied magnetic field on the electric quadrupole frequency shift was investigated, leading to the determination of the vapor cell's asymmetry parameter η and the average twist angle ⟨θ⟩ of nuclear spin-wall collisions. Furthermore, the temperature dependence of the electric quadrupole frequency shift in 131Xe atoms was characterized, enabling the extraction of the desorption activation energy (E A ) of 131Xe on the MEMS vapor cell surface. By analyzing the free induction decay (FID) signals of 129Xe and 131Xe at varying temperatures, the relationship between their relaxation rates and temperature was established. These findings offer valuable insights for optimizing nuclear spin relaxation times in microatomic gyroscopes.